亨利．西季威克的《倫理學方法》與實踐理性二元論

Henry Sidgwick's Methods of Ethics and The Dualism of Practical Reason

邱奕凱(Chiu Yi-Kai)

指導教授 ： 陳建綱

國立政治大學/社會科學學院/政治學系/碩士(2019年)

https://doi.org/10.6814/NCCU201900585

摘要

本論文聚焦於Henry Sidgwick（1838-1900）的倫理學思考，主要討論其著作《倫理學方法》（Methods of Ethics）之相關問題，該書細緻的論證了三種普通人判斷道德責任的方法：自利主義（Egoism）、直覺主義（Intuitionalism）與效益主義(Utilitarianism)，檢視這三種方法如何運作並討論三者的相互關係。關於自利主義與效益主義的統整上，他發現人們對於關乎自身利益與關乎集體利益兩者所做出的道德判斷指向了兩個不同的極端，難以在理論上統合，在實踐上也就有了兩個不同的標準。Sidgwick稱其為「實踐理性二元論（The Dualism of Practical Reason）」的困境，此為本篇論文最核心的問題意識：Sidgwick如何導出此結論？二元論的內涵和意義為何？本文首先從歷史出發，描繪形塑Sidgwick理論的背景，其中包含其個人生長經歷，以及他所承襲的學派。此部份重點在於呈現Sidgwick獨特的「直覺主義式效益主義」，他將幾股對立的思潮，凝聚成為自己特別的理論。接著闡述《倫理學方法》的實質內容，主要關於理性（reason）、應當（ought）及正確（right）等概念的涵義，以及直覺主義——常識道德與效益主義如何連結，並且由此展開關於實踐理性二元論的描述。此問題是Sidgwick對Bentham及Mill的修正，他試圖從理論面而非實踐、應然而非實然導出一個單一的倫理原則，最後產生的失敗。本文最後一部份是關於實踐理性二元論的詮釋，主要的切入點是Sidgwick對常識的重視而透露出的保守主義色彩。此種做法限縮了理性作用的空間，影響了兩種方法的證成。而本文亦發現，自利主義在ME中的證成是不完整的，那麼為何它足以成為對立於效益主義的另一個倫理方法？本文的回答時，Sidgwick此部分的書寫隱含對個人自由的保障，劃分出一塊不可為集體利益吸收的個人自利考量。

關鍵字

效益主義 ； 直覺主義 ； 實踐理性二元論 ； 倫理學方法

並列摘要

This thesis focuses on the ethical thinking and related discussions of Henry Sidgwick’s Method of Ethics (ME). In this book, Sidgwick elucidated and discussed the mutual relations of three kinds of methods that are used in common people’s moral thinking: Egoism, Intuitionalism and Utilitarianism. In terms of the unifying of Egoism and Utilitarianism, Sidgwick discovered that the moral decisions made by common people when they concern about their own interests and about public interest point to two different directions; thereofore, it can not be easily unified as one in theory. Sidgwick called this difficulty as “the Dualism of Practical Reason”. How did he reach this conclusion, and what are the meaning and implication of it? I will start to answer these questions from historical perspective, describing the background of Sidgwick’s early life which has a great influence on his theory and the schools of thought that Sidgwick inherited. The importance of this historical review is to show how Sidgwick created his unique “Intuitional Utilitarianism” by fusing theories which contradict each other. Then I will describe the meaning and related arguments of Reason, Right and Ought in ME as well as how Intutionalism (Common Sense Morality) connects with Utilitarianism. The definition Sidgwick gave to these concepts and the connection between the two methods partly form the Dualism. In addition, the failure of Dualism was a result of his effort to modify Bentham and Mill’s theories by trying to get one ultimate moral criterion from theorical instead of practical point of view. In the final chapter of this thesis, I will elucidate how Sidgwick took Common Sense to justify other two methods and thus restricted the realm of Reason. I regard this as the conservative aspect of Sidgwick’s ME. Besides, I found that the justification of Egoism Sidgwick gave is not complete, which can be a breach leading Egoism to Utilitarianism. However, the conclusion of Dualism of Practical Reason shows that Sidgwick intended to use Egoism to conter Utilitarianism for the purpose of preserving a realm of individual freedom.

並列關鍵字

Utilitarianism ； Intuitionalism ； Dualism of practical reason ； Methods of ethics

參考文獻

中文部分

亨利・西季威克著，廖申白（譯），1995。《倫理學方法》。台北：淑馨出版社。

約翰・斯圖亞特・穆勒著，邱振訓（譯），2017。《效益主義》。新北：暖暖書屋文化。

約翰・斯圖亞特・穆勒著，許寶騤（譯），2017。《論自由》。北京：商務印書館。

陳江進，2013。《功利主義與實踐理性－西季威克道德哲學思想研究》。北京：人民出版社。